#include <cstring>
#include <iostream>
#include <algorithm>

using namespace std;
const int N =100010, M = 200010;

int n, m;
int h[N], e[M], ne[M], idx;

int color[N];

void add(int a, int b)
{
    e[idx] = b, ne[idx] = h[a], h[a] = idx ++;
}

bool dfs(int u, int c)
{
    color[u] = c;
    for(int i = h[u]; i != -1; i = ne[i])
    {
        int j = e[i];
        if(!color[j])
        {
            if(!dfs(j, 3-c)) return false;
        }
        else if(color[j] == c) return false;
    }

    return true;
}

int main(){
    scanf("%d%d", &n, &m);
    memset(h, -1, sizeof h);
    while(m --)
    {
        int a,b ;
        scanf("%d%d", &a, &b);
        add(a, b);
        add(b, a);

    }
    bool flag = true;
    for(int i = 1; i<= n; i ++)
        if(!color[i])
        {
            flag =false;
            break;

        }
    if(flag) puts("Yes");
    else puts("No");


    return 0;
}